Pretibial Pruritic Papular Dermatitis: A Case Report and Emphasis on Effective Treatment with Pentoxifylline.

Pretibial pruritic papular dermatitis (PPPD) is a distinctive skin disorder in response to persistent pretibial manipulation. Clinically, it manifests as multiple discrete, pruritic, flesh-colored-to-erythematous papules and plaques confined to the pretibial area. The histological hallmark of PPPD comprises irregular epidermal psoriasiform hyperplasia with parakeratosis and spongiosis, dermal fibrosis, and lymphohistiocytic infiltration. Due to its rarity and underrecognition, the prevalence and standard treatment of the disease have yet to be well elucidated. Here, we present a case of PPPD in a 60-year-old female presenting with numerous pruritic, erythematous-to-brownish papules and plaques on bilateral pretibial areas for 1.5 years. The lesions were significantly improved after 1 month of additional treatment with oral pentoxifylline. In this report, we aim to raise awareness in recognizing PPPD since it manifests unique clinical, dermoscopic, and histological features, representing pretibial skin's response to chronic rubbing. In addition, we proposed a novel effective therapy for the disease using pentoxifylline.